Steam boiler



R. GRAY STEAM BOILER Jan. 13, 1942.

, 1959 4 Sheets-Sheet 1 Filed June 23 ooo\oooo 000 0000 0000 0000 INVENTOR RGRAY BY ATTORNEY ml v m MA m w 0 m5 H W-mm NL 1 U M" la m n L m ATTORNEY mu u mmu n .WMMMMHMHWMMWMmmN OOOOOO 00000-1 2," OOOOO R GRAY STEAM BOILER Filed June 23, 1939 O 00000g OOOOO OOOOOO Jan. 13, 1942. R GRAY 2,270,048

STEAM BOILER Filed June 23, 1939 4 Sheets-Sheet 4 .Y: i I i i INVENTOPv R. G RAY ATTORNEY Patented Jan. 13, 1942 UNITED STATES r oirrl'ca This-invention relates to improvements in steam boilersand has for its object theprovision of a'sectional boiler composed of shop fabricated sheet metal um'ts capable of beingeasily assembled at the place of use -to provide a self-contained installation which is of simple design, easy to clean and operate and is free from the use of refractory materials-- Other objects, advantages and characteristic features of the invention will be readily understood from 'the '-following detail description taken in connection with *the accompanying drawings,

in which Fig. 1 is a view; mainly in longitudinal section, of a boiler constructed 'in accordance with my invention.

Fig; 2 is a viewypartlyin 'endelevation and partly in vertical section, the plane of the section being substantiallyalong the line 2-2 of Figz'l. Fig. '3 is also a view 'partlyiin end" elevation and partly in vertical section, the planeof the sectionbeing substantially along'the line 33 of Fi 1'.

Fig. l is a viewpartly'in plan and partly in horizontalsection, the plane of the section being substantially along the line 4 4 of Fig. '1.

Fig; 5 is a detail view "showing one of the brackets by which. the boiler' shell is supported fromthe wall of the 'firebox;

Fig".""6 is a sectional viewtaken "along the line 6-6 of Fig. 5.

vFigf"? is a fragmentary sectional the line -"I of Fig. 4'.

Fig. 8 is a sectional view along the line '88 of Fig.7.

Fig. 9 is a detail sectional View showing a slight modification.

Inithese drawings the boiler drum, fire box and base of my'improved boiler are respectively indicated-at 5, 6 and 1.

Fire box 6 is formed by the assembly of a plurality of shop fabricated sheet metal'panel units of hollow construction. These units are generally indicated at 8; 9 and [0. Unit' 8' is made in the form'of a U-shaped panel including a central portion 8a and parallel side portions 811. The

View along centralportion 8a forms thefront wall of theme box while the side portions 812 form adjacent portions 'of the" sidewalls of the fire box and are butted against the intermediate side wall panels 9. Unit I ll also comprises a U-shaped panel whose central portion Illa forms the rear wall of the fire box and whose side portions Iflb are complete the side wall structure of the fire box.

. As hereshown each of the panels 8, 9 and It] also butted against the intermediate panels 9 to comprises spaced'inner and outer sheet metal walls l2 and i3 having. their edges welded to interposed sheet metal marginal Walls M. The inner and'outer sheet metal plates or walls I2 and I3 of each panel are also fastened together by rivetsor stay bolts I5.

The central portions 8a of the end panel 8 is recessed at I 6 to receive the boiler drum 5 which is provided with the usual fire tubes Ed. I Drum '5 is supported in place by brackets I! which rest on the upper edges of the side pordons-=8?) and I62) of the panel units'8 and H1. The central portion lila of panel unit I6 is spaced from the adjacent end'of drum 5 to provide an offtake flue I8 which is closed at the top by a wall 19 provided with a smoke outlet opening 26. The end of the boiler remote from the' ofitake flue 18 may be provided with the usual smokebox 2| shown in Fig. 1.

The fire box panels 8, 9 and H! are mounted on the base 'I' and welded or otherwise secured together to form the side and end walls of a combustion chamber which is divided into two compartments A and B by a hollow sheet metal bridge wall 23. The lower portion of bridge wall 23 is connected to boiler drum 5 by pipe 24 throughwhich the main flow of water is in the direction indicated by the applied arrows 25. This pipe 24 is located in the path of the gases travelling toward flue I8 and encloses a smaller pipe 26 whose upper'end is in open communication with the interior of the boiler drum 5. Pipes 24 and 26 are separated by an intervening annular space 27 which is in open communication with the lower portion of pipe 24. Owing to its location in the path of the highly heated gases pipe 24 is apt to be heated to a temperature such'that there may be a tendency toward a reversal of flow through said pipe, that is to say, there may be a tendency for the heated water in said pipe to flow upwardly instead of downwardly. When the additional pipe 26 is provided and arranged as described herein, the reversal of flow occasioned by excessive heating of pipe 24 is confined to a slight upward movement of the water in the annular space 27 and does not interfere with the main downwardfiow through pipe 24.

The panels 8, 9 and It] constitute hollow water walls through which water is circulated from the drum 5 and the hollow bridge wall 23. In this connection it will be noted that the Water chambers afforded by the central panels 9 are connected to the water chambers of the panels 8 and by the bypass connections generally indicated at 29 and 29a. The water chambers of the panels 9 are also in communication with the interior or water chamber of bridge wall 23 through openings 30. It will thus be seen that water from boiler drum flows downwardly through pipes 26 and 24 to the water chamber of bridge Wall 23 and from thence to the water chambers of the central side panels 9. The water thus supplied to panels 9 flows through bypass connections 29 and 29a to the Water chambers of panels 9 and Ill. The water is returned to the boiler drum from the upper portions of panels 8, 9 and I0 through the return connections indicated at 3|.

As here shown, each bypass connection 29 comprises a plurality of tubes 34 extending between headers 35 and 36, the header 35 being welded in place over an opening 31 provided in the outer wall I3 of panel 8 and the header 36 being welded over a similar opening 38 provided in the outer wall l3 of panel 9 (see Fig. 4) Each bypass connection 29a also comprises a plurality of tubes 40 extending between headers 4| and 42, the header 4| being welded to panel 9 over an opening 43 and the header 42 being welded to panel l0 over an opening M. V

The return connections 3| are formed by tubes 46 having their inner ends welded in openings provided in walls [2 of the panels 8, 9 and I0 and their outer ends welded in openings provided in small header boxes 41 welded to the boiler drum 5 over suitable openings 48.

While the drum supporting brackets I i may be of any suitable type I prefer to employ the construction shown in the present drawings. In this instance each bracket comprises a pair of side plates Ila having curved edges llb welded to the boiler drum 5. The plates I 1a are joined together and reinforced by a horizontal web plate llc which rests on the upper edges of one of the side walls of the firebox.

The base I on which the fire box 6 rests is here shown as comprising a rectangular frame consisting of channel irons welded together in end to end relation with the channels thereof facing outwardly. This base frame is utilized to support the fire box floor 50 which may be of any tical portions C and D lying in different vertical planes and joined together by an obliquely inclined intermediate portion E. By reason of this construction the previously mentioned flue space I8 is reserved between the central portion lila of panel In and the adjacent end of the boiler when the side portions 10b of said panel are abutted against the central panels 9 of the fire box.

The pipe connections 29 and 29a may be replaced by connections of the type shown in Fig. 9. In this case the adjacent walls M of abutting panels are provided with registering openings 50. A pipe 5! extends through these openings and serves as a connecting conduit between the water chambers of the panels. The ends of pipe 5| are fitted in and expanded against the walls of openings formed in the pipe supporting caps 52 which are welded to the walls l4. The pipe supporting caps 52 are sufiiciently resilient to provide for expansion and contraction of the pipe 5|, the latter being spaced from the walls of the openings provided in the wall members l4.

It may also be pointed out that the central panels 9 of the fire box may be omitted. In this case the side portions of the two U-shaped panels 8 and H) are butted together and their water chambers connected either by bypass connections of the type shown in Fig. l or by internal connections of the type shown in Fig. 9.

Another modification contemplated by the present invention is the omission of the bridge wall 23. When this element is omitted the pipe 25 is provided with branch connections to the water chambers of the oppositely located central wall panels 9 of the fire box.

Having now described what I consider to be the preferred embodiment and certain modifications of this invention. it will be understood that various other changes in the construction and arrangement of parts may be resorted to within the scope and spirit of the invention as defined by the appended claims.

Having thus described my invention, what I claim is:

1. A boiler assembly comprising a fire box provided with hollow front, rear and side walls of equal height, the upper portion of the front wall being shaped to provide a substantially semicircular boiler drum receiving recess and the rear wall being shaped to provide upper and lower vertical portions lying in different vertical planes and joined together by an obliquely inclined intermediate portion, the distance between the front wall and the upper vertical portion of the rear wall being substantially greater than the distance between the front wall and the lower vertical portion of the rear wall, a boiler drum fitted in the recess of said front wall with the rear portion of the drum overhanging a part of the obliquely inclined intermediate portion of said rear wall and with the extreme rear end of the drum spaced from the upper vertical portion of said rear wall, a bafile bridging the space between the rear end of the drum and the said upper vertical portion of the rear wall, and water circulating conduits interconnecting the water spaces of the boiler drum and the walls of the fire box, one of said conduits extending downwardly from the lower rear portion of the drum through the obliquely inclined intermediate portion of said rear wall and thence forwardly in a horizontal plane below the lower edges of all of said walls, and means connecting the horizontally extending portion of said conduit to the lower portion of the water spaces of the side walls of the fire box.

2. A boiler assembly as recited in claim 1 in which the last mentioned means comprises a hollow bridge wall extending between the side walls of the fire box in communication with the water spaces of said walls, said hollow bridge wall being located between and in spaced relation to the lower portions of the front and rear walls.

ROBERT GRAY. 

